Treating furnace-gases.



U. WEDGE.

TREATING FURNAGB GASES.

APPLICATION FILED JAN.11, 1910.

Patented Sept. 24, 1912.

2 SHEETS-SHEET 1.

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U. WBDGB.

TREATING FURNAUE GASES.

APPLIOATION rILBD JAN. 11, 1910.

Patented Sept. 24, 1912.

2 SHBBTSSHBET Z Ilui'llillllli UNITED sTATEs PATENT oEEIoE.

UTLEY WEDGE, OF ARDMORE, PENNSYLVA-NIA.

TBEATING FURNACE-GASES.

tain Improvements in Treating Furnace- Gases, of which the following is a specication. f

The object of my invention is to increase the percentage of Ysulfur dioxid in gases from furnaces' or converters for smelting pyr-ites, suld ores, copper matte or the like orto separate from the sulfurfdioxid, either wholly or in-part. the carbon dioxid, and `l:uch 'other impurities'or adulterants as may be combined with said sulfur dioxid in the furnace gases, the enriched gases or the sulfur dioxld obtained therefrom being thereby availablel for effective subsequent use, as for instance e in the manufacture of sulfuric or sulfurous acid. This object IN attain in the Cmanner hereinafter set forth, reference being had to vthe accompanying drawings, in which- Figure 1 is a plan or top view illustrating,

in diagrammatic form, apparatus. 'for the practice of my invention, and Figs. Q, 3 and 4 are vertical sectional views, on an enlarged scale, of certain elements of 'said apparatus.

Previous to my invention,'it has been customary to utilize for `the manufacture of sulfuric acid, gases issuing from a furnace of t-he character before referred to, the gases being passed first through a Glover tower, wherein they are mixed with nitrous fumes in theusual manner, the mixed gases being then carried to lead chambers wherein they are further mixed with steam, as in accord ance with the' ordinary method of` producing sulfuric acidby what is known as the 40 chamber )recess or the Gases have been brought into contact with' oxidizing or catalytic material, as in the Contact process. For the .economical working of either process, however, the proportion o t' sulfur dioxid in the gas should be fairly um formV and as high as practicable, and not below seven per cent. of the volume of gas. The gases, however, usually contain a much lower percentage of sulfur dioxid than-the above not-ed minimum, which percentage is likelyto be very variable. with the'result that the -amount of sulfuric acid produced v Speeiicaticn of`v Letters Patent.

Application tiled January 11, 1910. Serial No.

Patented Sept. 24, 1912. 537,4;45;

from a given quantity of the gases, or a given chamber space, is small andthe cost of manufacture high, furthermore, the low pere Ncentage of sulfur dioxid contained in some of the furnace gases would necessitate the use of lead chambers of such enormous di-v mensions as to be impracticable. In .carry, ing out my invention, therefore, I so Atreat the furnace gases as to-very materially increase the percentage of sulfurfdioxid in the gases employed in the acid producing apparatus, and `I am therefore enabled to greatly increase the quantity of sulfuric acid Ipensions of the chambers within the bounds of practicability.

In` Fig-l of the drawings, l represents the furnace, 2 the main which receives the gases from said furnace, 9, a dustcollector or separator, 3 the ordinary Glover tower, 4 what. I term a.concentrator, 5 what l term a saturator, 6 what I term a regusulfuric acid apparatus.

The concentrator is shown in Fig. 2 and consists of a tower of any suitable crosssectional shape and height, this tower being properly supported in a pan 9 so that the side Walls of the tower are luted in the usual manner when the pan is filled with water or 'other liquid.

Communicatino with one side of the tower, near the bottom of the latter, is an the furnace gases, and near the'to-p of the tower is a gas *outlet pipe 1l., another gas outlet pipe l2 communicating with the tower at an intermediate point. y

At the top of the tower is a Water supply pipe 13 which communicates with the interior of the tower through a series of properly sealed or luted openingslt, or through` other and equivalent means whereby tht.I water may be separated into a number of small streams orls rays distributed throughout the area of tie towerand falling into the body of water contained in the pan S) at the base of the tower.

It may be advisable in many cases to provide the tower with a mass of refractory material which will provide innumerable chanproduced, and, when the chamber process is employed, am enabled tc restrict the div lator and wone of the lead chambers of the Y inlet pipe 10 for supplying the tower with nels for the upward flow of gas and the downward flow of water as is customary in gas washers or scrubbers, the purpose of the tower being to bring the ascending gases into intimate contact with the descending and finely divided body of water.

The capacity of water to absorb sulfur dioxid is dependent upon its temperature, water at a temperature approaching the boiling point only absorbing about one-tenth of one per cent. -by weight of sulfur dioxid and its absorbing capacity increasing as its temperature decreases until, at a temperature of 60o F., it can absorb or dissolve nine and four-tenths per cent. of its weight of sulfur dioxid.

Supposing therefore that water enters the top of the tower at a temperature approximating 600 F., while blast furnace gases enter the lower portion of the tower at a temperature considerably exceeding the boiling point of water, the result will be a gradually increasing rise in the temperature of the water as it Hows from the top of the tower to the bottom of the same, and a constantly increasing capacity of the water to absorb or dissolve sulfur dioxid as the gases containing the same rise from the bottom toward the top of the tower.

In Fig. 2 of the drawing, I have indicated at the left hand side of the tower the gradual increase in the temperature of the water as it flows downwardly and beside the tower at the left, I have indicated the gradually increasing capacity of the Water to take up sulfur dioxid as its temperature decreases toward the top of the tower.

By properly regulating the supplies of water and furnace gases admitted. to the tower, all or substantially all of the sulfur dioxid contained inthe gases will be absorbed by or dissolved in the water in the passage of the gases from the bottom to the top of the tower the large absorbing capacity of the cold water in the top of the tower rendering it impossible for any material percentage of sulfur dioxid to escape at the top of the tower if a ortion of the gases rich in sulfur dioxid 1s allowed to escape from the tower at a lower point. Gases escaping at the pipe 11 will, in such case, consist mainly of atmospheric air, carbon dioxid and nitrogen, the two latter being much less soluble in water than is `sulfur dioxid. As

the water descends in the tow er, and its temperature rlses, its capacity to retain the sul y fr dioxid decreases and the latter will be driven off, consequently, if an escape pipe is provided, at what may be termed a neutral point, say at th'e position of the pipe 12, corresponding with a water temperature of 120O F., or thereabout,.and a portion of the gases are withdrawn from the column of furnace gases at this point, the gas thus withdrawn will contain practically all of the sulfurldioxid originally contained in the full volume of gases entering the tower at the bottom of the same. If, therefore, the entering gases contain, say four per cent. of sulfur dioxid and one-fourth ofthe total volume of gases is withdrawn at the pipe 12, the gases thus withdrawn will contain 16 per cent. of sulfur dioxid.

At the right hand side of Fig. 2, I have indicated the respective percentages of sulfur dioxid contained in the ascending volurne of furnace gases.

It is impossible for any considerable quantity of sulfur dioxid to be carried out in solution in the water escaping at the bottom of the tower because of the high temperature of the water at that point.

That portion of the furnace gases containing 4 per cent. of sulfur dioxid conveyed directly to the Glover tower 3 and mixed therein with the nitrous fumes pass from the Glover tower lthrough the pipe 20 to the lead chamber a@ and by combining with these gases a proper proportion of the enriched gases from the pipe 12, as through a pipe 12, the gases entering the lead chamber m may be enriched with sulfur dioxid to an extent which is subject to regulation and which will insure the economical production of acid in the lead chambers if the chamberprocess is employed, or the gases enriched with sulfur dioxid may be conveyed by the pipe 12,a directly to the point of contact with the oxidizing or catalytic material if the contact process is used. In some cases, however, I prefer to free the ysulfur dioxid from the carbon dioxid, nitrogen and other impurities or adulterants with which it may be combined in the gases issuing from the concentrator at the pipe 12, and for this reason I use in connection with the concentrator 4 the saturator 5 and the regulator 6.

The saturator 5 as shown in Fig. 3 consists of a tower which may be substan tially similar to the tower and which re` ceives in its lower portion the gases from the pipe 12, these gases as they rise being brought intoA contact with the descending body of'water introduced by the supply pipe 16 at the top of the tower and distributed throughout the area of the tower by a contained mass of refractory materialor in any other convenient way, the water being removed from the bottom of the tower 15 at as low a temperature as possible and saturated with sulfur dioxid, the remaining gases which have been freed from the sulfur dioxid escaping at the pipe 18.` escapes at a temperature of C F., for example, it. should contain about seven and nine-tenths per cent. by weight of sulfur dioxid and it is then conveyedV through a If the water pipe 17 to the regulator 6 in which it is heated so as to drive off the sulfurdioxid,

' the latter accumulating in the upper portion of the regulator in a substantially pure or only slightly Vdiluted state, and being conveyed therefrom through a pipe 19 to the pipe 20 which receives the gases from the Glover tower, or directly to the contact apparatus.

' The regulator is shown in Fig. 5 and consists of a tower substantially similar to that of the concentrator'and saturator, the` water, with sulfur dioxid ,in solution therein, entering thjstower. at the top through the pipe 17, and, Yas it descends being brought. into contact with ascending volumes of hot furnace gases which enter the tower near the bottom through a pipe '22, directly from r'the dust 'collector or separator 2, In operthe amount of water-containing sulfur dioxld which is supplied -to vthe tower, varies in accordance with the amount of sulfur `dioxid required to give the desiredl percentage in the-acid ap aratus, while the amount of water admitted) to the saturatorv tower issulcient to take up the entire amount of sulfur dioxid from the gas entering the saturator through the pipe 12- from the concentrator.

The volume of hot gas admitted to the regulator from the dust collector 2a is controlled to Icorrespond with 'the amount of water saturated with sulfur dioxid which enters the top of the regulator, the object being to heat this water to a temperature vat vornear its boiling point. The water entering lthe upper portion of the regulator is, however, cold enough to condense any steam vwhich may `be generated in the lower por- 'tion of the regulator. The sulfur dioxid therefore escapes from fthe'regulator tower in a comparatively pure state, being diluted slightly -by the gases employed for heating the water to the ,boiling point in said tower.

Other heating agents than the vfurnace gases may lbe used for the heating of the Water in the regulator, .the heating of the water in the regulator by direct contact with the furnace gases being adopted simply as the cheapest 4and most convenient method of attaining the desired zresult.

The various pipes and lues of the apparatus may be provided with such valves Vor damper-sas maybe necessary to control or Iregulate the volume of iflow therethrough.

Of-'the total volume'o'f gases issuing from 'the furnace, '-the respective 'percentages conL veyed to vtheiGlover towel-.3, concentrator 4 and regulator '-6 will'be dependent upon cirno fixed formulafcan'berelied upon, practice ldetermining the -distribution of the gases best adapted'ft secure the desired results in any particular It will, of course, be understood that although I have shown the concentrator, saturator and regulator each in the form of a single tower, the number of towers'corrstituting each' of .these elements ofthe appa- 7o ratus may be multiplied to any desired extent, and the enriched gases may be removed between successive towers of the concentrator, if desired, and in some cases,.instead of supplying the Glover tower with the furnace as containing a low percentage of sulfur ioxid, I may supply said Glover tower with the enriched gases iowing from the pipe 12 of the concentrator, in which case, however, it may be necessary to raise the temperature 5 of the enriched gases before admitting them tothe Glover tower. It will be understood, further, that the construction and arrangement of the various elements of the apparatus shown in the drawings is only diagrammatic and is adopted simply for the purpose of conveyin an understanding of my invention and wit -out any attempt to represent either the details of the different structures or a necessary arrangement of the various elements of the apparatus.

I claim:

1. In the process of producing sulfuric or sulfurous acid from furnace gases, the mode herein described of increasing the percentage of sulfur dioxid in said furnace gases, said mode consisting in causing said gases to flow `in contact with a flowing body of water which, in its relation to the flow of the gases, is of gradually decreasing temperature and has a progressively increasin power of absorbing or dissolving sulfur d1- oxid, and removing a portion of the gases at the point where the desired enrichment of i the same with sulfur dioxid has been effected.

2. In the process of producing sulfuric or sulfurous acid from Vfurnace gases, the mode herein described of increasing the percentage of sulfur dioxid Iin said furnace gases, said mode consisting in causing said gases to 4flow in contact with a flowlng body of water which, in its relation to the iow of the gases, is of Igradually decreasing temperature and `has al progressively increasing =115 power of absorbing or dissolving sulfur dioxid, removing a portion of the gases rich in sulfur dioxid, at an intermediate point of the gas flow, and removing the remainintg gases, substantially free from sulfur dioxi 120 at the point where the flow of the gases in 'contact with the water terminates. a

3. In the process of producing sulfuric or sulfurous acid from furnace gases, the mode Iherein described of increasing the percent- 125- age'of sulfur dioxid in said furnace gases, said mode consisting in causing said ases to flow in contact with a flowing and nely divided body of water, which, in its relation to the flow of the gases, is of gradually decreasing temperature and has a progressively increasing power of absorbing or dissolving sulfur dioXid, and removing a portion of the gases at a point where the desired enrichment of the same with sulfur dioXid has been effected.

4. In the process of producing sulfuric or sulfurous acid from furnace gases, the mode herein described of `increasing the percentage of sulfur dioxid in said furnace gases, said mode consisting in causing said gases to flow in contact with a flowing and finely divided body of water, which, in its relation to the fiow of the gases, is of gradually decreasing temperature and has a progressively increasing power of absorbing or dissolving sulfur dioXid, removing a portion of the gases rich in sulfur dioXid, at an intermediate point of the gas flow, and removing the remaining gases, substantially free from sulfur dioXid, at the point where the flow of the gases in contact with the water terminates. l

5. In the process of producing sulfuric or sulfurous acid from furnace gases, the mode herein described of increasing the percentage of sulfur dioXid in said furnace gases, said mode consisting in subjecting an upwardly flowing stream of the gases to the action of a downwardly flowing body of water which, in its relation to the flow of the gases, is of gradually decreasing temperature andshas a progressively increasing capacity for absorbing or"dissolving sulfur dioXid, and removing a portion of the gases at the point where-their 'desired enrichment with sulfur dioXid has been effected.

6. In the process of producing sulfuric or sulfurous acidfrom furnace gases, the mode herein described'of.l increasing the percentage of sulfur dioXid in said furnace gases, said mode consisting in subjecting an upwardly flowing stream of the gases to the action of a downwardly flowing body of water which, in its relation to the iow of the gases, is of gradually decreasing temperature and has a progressively increasing capacity for absorbing or dissolving sulfur dioXid,`removing a portion ofthe gases rich in sulfur dioXid at an intermediate point of the gas flow, and removing the remaining gases, substantially free from sulfur dioxid, at the point wherethe flow ofthe gases in contactwith the water terminates.

7. In the process of producing sulfuric or sulfurous acid from furnace gases, the mode herein described of increasing the percentage of sulfur dioXid in said furnace gases,"said mode consisting in subjecting an upwardly flowing stream of the gases to the action of a downwardly flowing and finely divided body of water which, in its relation t0 the flow of the gases, is of gradually decreasing temperature and has a progressively gases, said mode'consisting in subjecting an upwardly flowing vstream of the gases to thev action of a downwardly flowing and finely divided body of water which, in its relation to the flow of the gases, is of gradually decreasing temperature and has a progressively increasing capacity for absorbing or dissolving sulfur dioxid, removing a portion of the gases rich in sulfur dioxid, at

Aan intermediate point of the gas flow, and

removing the remaining gases, substantially free from sulfur dioXid, at the point where the flow of the gases in 'contact with the water terminates.

9. In the process of producing sulfuric or sulfurous acid from furnace gases, the

mode herein described of increasing the percentage of sulfur dioxid in said Ifurnace gases, said mode consisting in subjecting an upwardly flowing and finely divided stream ofthe gases to the action of a downwardly fiowing and finely divided body of water which, in its relation to the flow of the gases, is of gradually decreasing temperature and has a progressively increasing capacity for absorbing or dissolving sulfur dioXid, and removing a portion of the gases at the point where their desired enrichment with sulfur dioXid has been effected.

10. In the process of producing sulfuric or sulfurous acid from furnace gases, the mode herein described of increasing the percentage of sulfur dioXid Vin said furnace gases, said mode consisting in subjecting an upwardly flowing and finely divided stream of the gases to the action of a downwardly flowing and finely divided body of water which, in its relation to the flow of the gases, is of gradually decreasing temperature and has a progressively increasing-capacity for absorbing or dissolving sulfur dioxid, removing a portion of the gases rich in sulfur dioxid at. an intermediate point of the gas flow, and removing the remaining gases, substantially free from sulfur dioXid, at the point where the flowrof the gases'in contact with the water terminates.

1l. In the process of producing sulfuric or sulfurous acid from furnace gases, the

g mode vherein described of separating sulfur dioXid from said furnace gases containing carbon dioXid or other impurities or adulterants, said mode consistingincausing said gases to flow in contact with a fiowing stream of water which, in its relation to the gas flow, is of gradually decreasing tem- .sulfuric perature and has a progressively increasing capacity for absorblng or dissolving sulfur .f dioxid, removing a portion of said gases at the point where ltheir desired enrichment with .sulfur dioxid has been effected, and then bringing said removed gases into contact with a further body of water whereby the sulfur dioxid is absorbed or dissolved, and the gases with which it had been mixed are-set free.

12. In the process of producing sulfuric i or sulfurous acid from furnace gases, the

mode herein ydescribed or separating sulfur' dioxid from [said furnace gases containing carbon dioxid or other impurities or adulterants, said mode consisting in causing said gases to flow in contact with a flowing stream of water which, in its relation to the gas flow, is of gradually decreasing temperature and has a progressively increasing lcapacity for' absorbing or dissolving sulfur dioxid, removing a portion of the gases rich in sulfur dioxid at an intermediate point of the gas flow, removing the remaining gases,

free. 13. In the process of substantially free from sulfur dioxid, at the point where the flow of the gases in contact with the water terminates, and bringing the enriched gases into contact with a further body of water, whereby the sulfur gas flow,V Vis of gradually' decreasing temperature and has a progressively increasing v capacity for absorbing or dissolvingsulfur l gases to flowY in contact with a flowing dioxid, removing a portion of said gasesat the point Where their desired enrichment with sulfur dioxid has beenfefectedfthen bringing said removed gases into' con-tact witha further body of water whereby the sulfur dioxid is absorbed or dissolved, and the gases with which it had been mixed are set free, and then heating the water to. drive off the sulfur dioxid contained therein.

`14. In the process of producing sulfuric or sulfurous acid from furnace gases, the

mode herein described of separating sulfur.

dioxid from said'furnace gases containing ,carbon dioxid or other impurities or. adul.

terants, said mode consisting in causing said stream of water .which,in its relation to the gas flow, is of gradually decreasing temperature and has 4a progressively increasing capacity for absorbing or dissolving sulfur dioxid, removing a portion of the gas rich in sulfur dioxid at an intermediate point of thegasflow, removing the remaininggases, substantially free from sulfur dioxid, at the point .where the flow of the gases in contact with the water terminates, bringingthe enriched gases into contact with a further body of water, whereby the sulfur dioxid isabsorbed or dissolved and the gases with which it had been mixed are set free, and' then heating `the water to drive off the sulfur dioxid contained therein.

15. In the process of producing sulfuric or sulfurous acid from furnace gases, the mode herein described of obtaining sulfur dioxid from said furnace gases, said mode consistingin causing said gases to flow in contact with a flowing body of water, which, in its relation to theflow of the gases, is of gradually decreasing temperature and has a progressively increasing capacity for absorbing or dissolving'sulfurdioxid, removing aportion of said gases at a point where their desired enrichment with sul-fur dioxid has been effected, bringing said enriched,

vsuch heat.

.16.,Inthe process of producing sulfuric or sulfurous acid from furnace gases, the mode yhereindescribed of obtaining sulfur dioxid from said furnace gases,vsaid mode consisting in causing said gases to flow in contact with a flowing body of water, which,

in its relationto the flow of the gases, is of gradually decreasing temperature and has 'a progressively increasingu-'capacity for abr dioxid, remov .ing a portionof the. gases rich in sulfur di- Y oxid `at .an Aintermediate .point of the gas sorbingor dissolving.v sul flow, .removing the remaining gases, substantially rfree from sulfur'dioxid, at the point where :the .flow lofv the fgass in contact withV the ,water terminates," bringing the enriched; gases into contact with a further body of-iwater whereby4 the sulfur dioxid is absorbed Vor dissolved "and the gases with .which itl had been mixed are set free, heating said 'water 4to=drive off thesulfur dioxid therefrom, and utilizing the furnace gases 'for `the supply of such heat.

417. The mode herein described of effectingthe production of sulfuric or sulfurous acid 4from .furnace gases, said mode consisting in'ipassing aportion of the furnace Jgases through the Glover tower of the acid apparatus, owing another portion of -said .gases in contact with a flowing body of water, which, in its relation to the gas flow,

.is of. gradually decreasing temperature and has a progressively increasing Acapacity for absorbing .or dissolvin sulfur dioxid, removing a portion of said gases at. the point 18. The mode herein described of producl ing sulfuric 'or sulfurous acid from furnace gases, said mode consisting in flowing a port-ion of said gases through the Glover tower `of the acid apparatus, flowing another portion of said gases in contact with a flowing body of water, which, in its relation to the gas flow, is of gradually decreasing tempera-ture and has a progressively increasing capacity for absorbing or dissolving sulfur dioxid, removing a portion of the gases, rich in sulfur dioXid, at an intermediate point'of the gas flow, removing the remaining gases, substantially freefrom sulfur dioXid, at the point where the flow of the gases in contact with the water terminates, and combining the enriched gases, in regulated quantity, with the gases flowing from the Glover tower, to produce in said gases the desired percent-age of sulfur dioXid for their further treatment in the acid apparatus and then converting into acid the sulfur dioxid thus obtained.

19. The mode herein described of producing sulfuric or sulfurous acid from furnace gases, said mode consisting in flowing a portion o-f said gases through the Glover tower of the acid apparatus, flowing another4 portion of said gases in contact with a flowing body of water, which, in its relation to the gas flow, is of gradually decreasing temperature and has a progressively increasing capacity for absorbing or dissolving sulfur dioXid, removing a portion of the gases at the point where their desired enrichment with sulfur dioXid has been eected, bringing said remaining gases into contact with a further body of water whereby the sulfur dioXid'is absorbed or dissolved and the gases with which it had been mixed are set free, heating said water to drive off the sulfur dioxid therefrom, and then combining said sulfur dioXid, in regulated quantity, with the gases flowing from the Glover tower to produce, in said gases the desired percentage of sulfur dioXid for their furthertreatment in the acid apparatus and then converting into acid the sulfur dioxid thus obtaine 20. The mode herein described of producing sulfuric or sulfurous acid from furnace gases, said mode consisting in flowing a portionA of said gases through the Glover tower of the acid apparatus, flowing' another portion of said gases in Contact with aflowing body of water, which, iniits relation to the sulfur dioXid, at an intermediate point of the gas flow, removing the remaining gases, substantially free from sulfur dioxid,'at the point where the flow of the gases in contact with the water terminates, bringing the enriched gases into cont-act with a further vbody of water, whereby t-he sulfur dioXid is absorbed or dissolved and the gases 'with which it had been mixed are set free, heating said water to drive olf the sulfur dioXid therefrom, and then combining said sulfur dioxid in regulated quantity with the gases flowing from the Glover tower to produce in said gases the desired percentage of sulfur dioxid for their treatment in the acid appaiatusl and then converting into acid the sulfur dioxid thus obtained.

21. The mode herein described of producing sulfuric or sulfurous acid from furnace gases, said mode consisting in ilowing a por- .tion of said gases through the Glover tower of the acid apparatus, flowing another portion of said gases in contact with a flowing body of water, which, in its relation to the gas flow, is of gradually decreasing temperature and has a progressively increasing capacity to absorb or dissolve sulfur dioXid, removing a portion of the gases at the point where their desired enrichment with the sulfur dioxid has been effected, bringing said enriched gases into contact with a further body of water, whereby the sulfur dioXid is absorbed or 'dissolved and the gases with which it had been mixed are set free, heating saidwater to drive ofl'l the sulfur dioXid therefrom, utilizing the furnace gases forl the supply of such heat, and then combining the sulfur dioXid, in regulated quantity, with the gases flowing from the Glover tower, toy

produce in said gases the desired percentage of sulfur dioxid for their further treatment in the acid apparatus and then converting into acid the sulfur dioxid thus obtained. y

22. The mode herein described of producing sulfuric or sulfurous acid from furnace gases, said mode consistingv in flowing a portion of said gases through the Glover tower of the acid apparatus, flowing another portion of said gases in contact with a flowing, body of water, which, in its relation to the gas flow, is of gradually decreasing temperature and -has a progressively increasing capacity to absorb or dissolve sulfur dioXid, re-

. moving a portion of the gases, rich in sulfur dioxid, at an intermediate point of the gas flow, removing the remaining gases, substantially free from sulfur dioXid, 'at the point where the How of the' gases in contact with the water terminates, bringing the enriched 'gases into contact with a further body of water, whereby the sulfur dioxid is absorbed or dissolved and the gases with which it had been mixed are set free, heating said Water to drive off the sulfur dioxid therefrom, utilizing the furnace gases for the supply of such heat, and then combining the sulfur dioXid, in regulated quant-ity, with the gases flowing from the Glover tower, to produce in said gases the desired percentage of sulfur dioxid for their further treatment in the acid apparatus and then converting into acid 10 the sulfur dioxidthus obtained. In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses. i

' UTLEY WEDGE. Witnesses:

KATE A. BEADLE, HAMILTON D. TURNER. 

